Scoliosis, known also by the terms idiopathic scoliosis, spinal curvature and lardoscoliosis) is a deviation from a normal spine in three directions or planes: frontal (coronal), lateral (sagittal) and transversal (axial). While ten percent of the population will have some spinal curvature, no more than three promilles require extensive medical treatment. Scoliosis may be present due to underlying muscle or nerve problems, a defect in bone formation or due to unknown reasons, i.e., idiopathic scoliosis. Idiopathic scoliosis, and particularly its adolescent type, may affect up to three percent of the adolescent population. One treatment is provided by a scoliosis brace, which is an orthosis adapted to hold the spine in a straighter position. The brace is prescribed by an orthopedic specialist and is usually worn constantly and continuously until bone growth has stopped.
As set forth above, scoliosis is a complex 3-D deformation of the trunk, spine and rib cage. From the clinical point of view, the most prominent feature of this complex deformity is a sideward curvature of the trunk accompanied by the rib's hump. In such cases a rib hump is still present and even progresses with all its consequences. The list of clinical problems associated with scoliosis goes far beyond the pure cosmetic complaints. It includes a distortion of the abdominal and chest organs and therefore an alteration of their functional capabilities, alteration of a normal gait with associated pelvic obliquity and many other functional and psychosocial difficulties.
Unlike congenital scoliosis, which is caused by congenital anomalies of the spinal structure, for the idiopathic type of scoliosis no congenital anomalies of vertebras or rib cage are identified. This may partially explain the fact that to date, despite numerous attempts to identify the exact cause for this pathology it has not been not found. Therefore, the evaluation of medical methods of treatment is complicated and often empirical, and is based on the personal experience and beliefs of the surgeon. In fact, the principals of treatment of scoliosis have remained basically unchanged for the last 70 years.
Inventions disclosed in the art basically include different kinds of devices that permit some preservation of the natural spinal movement without compromising the stable holding properties of the fixation system.
Idiopathic scoliosis is not an acute illness, but with time the vertebrae become secondarily deformed. Surgeons who treat scoliosis know about the deformation of the scoliotic vertebrae, this deformity is especially prominent in computer tomography evaluation. Apical vertebrae are the most deformed and they appear twisted on the axial CT images.
It is acknowledged that less then ten percent of patients with idiopathic scoliosis will need a surgical correction. Fortunately, most of the patients are diagnosed during the early stage of the scoliotic progression and can be treated conservatively. For this purpose, different types of externally applied corrective devices were developed.
The idea of bracing for scoliosis treatment dates back to ancient times. Many attempts to stop the progression of structural scoliotic curves were performed in the past: forcible horizontal traction and suspension, corsets, casts and a variety of braces.
Long-term follow-up studies of patients treated with the Milwaukee-like braces indicate that the main effect of the brace is to halt the progression of moderate-degree scoliotic curves. U.S. Pat. No. 4,230,101 to Gold for example introduces an improved Milwaukee-style brace comprising upright metal bars and small straps that apply pressure to the spine. One of the well-known problems with this treatment is the issue of compliance with brace wear.
The Boston brace system was introduced in 1971 by John Hall and Bill Miller and is known worldwide as the standard for brace treatment. It is designed to be “active” by means of constantly applied de-rotation forces, but these forces are produced by the static arrangement of the pads. U.S. Pat. No. 5,503,621 to Miller for example discloses a body brace which is a Boston-style brace made of a plastic body jacket that fits snugly around the body to exert pressure on the ribs and back, pushing the spine into a straighter position. These braces are considerably uncomfortable corset-like orthosis that apply non-constant and scattered twisting forces on the body of the patients. Moreover, permanent loss of the natural flexibility of the spine because of the solid fusion of the spinal column is the price paid to protect the surgically achieved correction. The data suggests that part-time brace use sometimes may be as effective as full-time use. Complete failure to use the brace, however, has an adverse prognosis. Control or net correction of idiopathic scoliosis treated by this brace was achieved in approximately 80% of the patients. But control of the curves with apexes above T7, triple curves, and curves in excess of 45 degrees appeared poor.
The Charleston bending brace, designed to be worn during sleep, was introduced in 1989 as an alternative to upright bracing but the effectiveness of the Charleston bending orthosis is even lower than the Boston brace. The average effectiveness for different types of bracing is 50% but compliance is suggested in the literature to be lower than for the Milwaukee brace.
Current indications for bracing scoliosis include children with at least one year or more of growth remaining, with curves of between 25 and 40 degrees and with apex of T8 or below and approximately 50% flexibility (Boston Brace course). In a prospective study of adolescent idiopathic scoliosis, female patients with curves between 25 and 35 degrees were treated with an underarm plastic brace. A successful outcome was obtained in 74% (curve progression no more than 5 degrees) compared to 34% of those who had no treatment. With increasing severity of the initially detected curve the prognosis for the outcome is worse.
Only recently have investigators began to search for true dynamic types of braces. One example of this may be the TriaC™ brace with a system of straps, but the amount of corrective forces that can be generated by this brace is limited and probably needs constant adjustment for effective use.
U.S. Pat. No. 5,599,286 to Labelle et al. discloses an elastic de-rotating orthopedic device, which applies a rotational force by means of stretchable strip or a plurality of such rubber-like strips. This corset is not strictly and firmly affixed to the body of the patient and thus applies for unfocused rotatory forces. Moreover, those forces are not homogenous and tend to decrease as time follows. Lastly, U.S. Pat. No. 5,840,051 to Towsley presents a flexible back and shoulder orthopedic brace for spinal applications. This orthosis contains body straps that are immobilized by an elongated trunk made of metal vertebrates stack affixed by means of two threaded poles. The spine of the patient is extended and pulled by the device along the main longitudinal axis of the device and only minimal rotatory forces are applied.
A cost-effective and convenient scoliosis brace, adapted for every day use which provides for pure and highly focused rotational forces at a predetermined and constant measure thus meets a long felt need.